[robomartin]

I am sure it is. However, the design uses very expensive custom boards to save a lot of weight. The build I was involved with used Odrives and that was enough to have issues. Pre-stretching the belts is also important.

If I had to guess I would suggest that, while 3D printing is a great enabling technology one of the issues it suffers from is that of tolerances. I'll preface this by saying I did not take any measurements at all on the parts as printed. If I did, I would not be surprised to discover issues that, in the aggregate, could lead to performance issues.